Effect of homogenization on the hot-deformation ability and dynamic recrystallization of Mg–9Gd–3Y–0.5Zr alloy
Effect of homogenization on the hot-deformation ability and dynamic recrystallization of Mg–9Gd–3Y–0.5Zr alloy
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DOI：
10.1016/j.msea.2009.03.060
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发表时间：
2009-07
期刊：
影响因子：
6.4
通讯作者：
Zhimao Yang;Jian-ping Li;J. X. Zhang;Yongchun Guo;B. W. Wang;F. Xia;M. Liang
中科院分区：
文献类型：
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作者：
Zhimao Yang;Jian-ping Li;J. X. Zhang;Yongchun Guo;B. W. Wang;F. Xia;M. Liang
Mg-9 Gd-3 Y-0.5Zr（wt.%）的两种状态（GW 93）合金，铸态（记为F状态）和均质化（记为T4状态），在应变速率为0.1s-1和温度范围从623 K到723 K下进行热压缩。建立了应力-应变曲线，并采用点计数法测定了动态再结晶（DRX）晶粒体积分数。结果表明，流变应力对压缩温度和预处理状态较为敏感。与铸态合金相比，T4态合金具有更高的流变应力和应变硬化速率θ，更复杂的变形组织，更小的动态再结晶速率和Avrami指数。这种现象是两种状态下初始形核位置不同和共晶粒子激发形核（EPSN）的结果。铸态合金的初始形核点包括原始晶界和共晶颗粒，而T4合金只有原始粗晶界可以作为形核点。
Two states of Mg–9Gd–3Y–0.5Zr (wt.%) (GW93) alloy, as-cast (note as F state) and homogenized (note as T4 state), were hot compressed at strain rate of 0.1s−1and temperatures range from 623K to 723K. The stress-strain curves were established and volume fractions of dynamic recrystallized (DRX) grains were determined using point counting method. The results show that flow stresses are sensitive to the compression temperature and pretreatment state. Comparing with as-cast alloy, T4 state alloy has a higher flow stress and strain hardening rate θ, more complicated deformation microstructures, a smaller dynamic recrystallization rate and Avrami exponents. The phenomena are the results of the difference of initial nucleation sites and eutectic particles stimulated nucleation (EPSN) of two states. The initial nucleation sites of as-cast alloy include the original grain boundaries and eutectic particles, but as for T4 alloy, only original coarse grain boundaries can be act as nucleation sites.